NFS: Fix a regression in the referral code

Fix a regression that was introduced by commit
0c2e53f11a6dae9e3af5f50f5ad0382e7c3e0cfa (NFS: Remove the unused
"lookupfh()" version of nfs4_proc_lookup()).

In the case where the lookup gets an NFS4ERR_MOVED, we want to return
the result of nfs4_get_referral(). Instead, that value is getting
clobbered by the call to nfs4_handle_exception()...

Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Tested-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -2464,8 +2464,7 @@ static int nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qst
 		case -NFS4ERR_BADNAME:
 			return -ENOENT;
 		case -NFS4ERR_MOVED:
-			err = nfs4_get_referral(dir, name, fattr, fhandle);
-			break;
+			return nfs4_get_referral(dir, name, fattr, fhandle);
 		case -NFS4ERR_WRONGSEC:
 			nfs_fixup_secinfo_attributes(fattr, fhandle);
 		}